ACTG 359 - This is a randomized, partially-blinded, multi-center study for HIV-1 infected patients who are failing treatment with the protease inhibitor indinavir. The study will compare various regimens (the soft gelatin capsule of saquinavir (SQV) in combination with ritonavir or nelfinavir and other drugs (delavirdine and adefovir dipivoxil) with respect to the proportion of subjects whose plasma HIV-1 RNA is below 500 copies/mL at 16 weeks. The study will also evaluate the safety, toxicity, and tolerance of the various therapeutic regimens. The primary therapeutic comparisons will be between ritonavir and nelfinavir, and between adefovir dipivoxil, delavirdine, and the combination. Additionally, three and four drug regimens will be compared.